Configurator, DuckDNS, Lets Encrypt and port forwarding (Update - Now broken!)

UPDATE: It seems everything I wrote below has broken my HA!
Nothing in the sidebar menu will work ,SNAPSHOTS, ADD-ON STORE and SYSTEM give a blank screen whilst DASHBOARD will show the Add-ons but selecting any of them gives a blank screen.
A message appears sometimes saying “Service system_log/write called.” which I am guessing relates to this message in the log: Unable to get property ‘root’ of undefined or null reference”

I think I need to (manually) uninstall Configurator?
Any help would be much appreciated!

----------- original post ----------
I am running HASS.IO on a Pi.
I have DuckDNS with Let’s Encrypt installed.
All good so far.

I installed the Configurator and added the iPanel but cannot start it from within HA presumably because I have to open port 3218.

However, if I open a separate browser to (NOTE: http not https) the Configurator opens and it seems like I can use it ok. I tried editing configuration.yaml to point to this URL but that didn’t work.

It would be nice to get this working from within HA.
Is that possible without opening the port on my router?

EDIT: this doesn’t seem to work, I get some very strange behaviour in the HA browser instance if the Configurator has been opened in a separate window.
I guess I’ll just stick with Notepad++

Configurator is better used outside HA for a couple of reasons, one, you can have HA in another window to refer to as you edit and two, the big one, when you restart HA you still have the files you changed open for editing, either to make more changes or to correct whatever you broke the last time.

Much more efficient way of working and no need to worry about https.

Yes, on reflection I agree that a separate window is better.
Now, if only I could get the page to work again…

Anyone got any suggestions why these links wouldn’t work?

I really hope I am not going to have completely reinstall HA from scratch.
(My last snapshot was several days ago and I have been tinkering a lot since then)